Herbert henry meyers



HERBERT HENRY MEYERS, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TOARMOUR UNITED srarns PATENT orricii.

qm um FERTILIZER WORKS, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

CONTACT PROCESS FOR MAKING SULFURIC ACID.

Application filed June 26,

' To all whom it may concern.-

Be it known that I, HERBERT H. Mnynus, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny,

Stateof- Pennsylvania, have invented certain new and useful Improvements in Contact Processes for Making Sulfuric Acid; and I do hereby declare the following be a 'full, clear, and exact description of the invention, such as will enable others skilled 4 in theart to which it appe-rtains to make making of and use the same.

This invention relates generally to the contact process for producing sulfur trioxid, or sulfuric acid. Inanother aspect, the invention relates to the production of a waterproduction of a Water-soluble double sulfate proposed, but, for

*of potassium and aluminum from alunite as a result of the use of raw alunite as the catalytic agent in the contact method.

In the contact method for. producing sulfur trioxid (SO, or sulfuric acid, numer ous catalysts or contact substances have beenone reason or another, none,ias far as is generally known to me, has proved commercially practicable, except platinum and iron oxid. The former, despite lts cost, is the most successful and widely used material, as it is possible to produce practically quantitative yields with it and, with proper precautions, its life as a catalyst is indefinitely long. Iron oxid, as a catalyst, is usually used in the form of iron pyrite cinder and, as such, is a.by-product of the. complete process, being produced when ironpyrites are burned to generate the necessary sulfur dioxid (S0 gas. Since the yields obtainable with iron oxid are comparatively low, it is pr ctically always used in conjunction with platinum or in. conjunction with a chamber system for producing sulfuric acid.

I have discoveredthat the mineral alunite, which is essentially hydrated basic double sulfate of potassium and aluminu may be very advantageously employed as the catalyst or contact substance in convertin gaseous mixtures containing sulfur clioxid and oxygen into sulfur trioxid. In fact, I have Specification of tettersratent.

'air, containing sulfur (l1OXl(l by volume and Patented Aug. 26, 1919. 1918. Serial No. 242,004..

found that alunite is a more efficient and effective catalytic agent than iron oxid.

The present invention, accordingly, involves, in the process of making sulfur trioXid by the contact method, bringinga gaseous mixture containing sulfur dioxid and oxygen into contact with mineral alunite in its raw or native state. lVorking at temperatures between about 450 C. and about 550 (1., with a mixture of sulfur dioxid and between 6.0% and 10.0% of therefore comparable to ordinary burner gas, I have attained, with raw alunite. as the catal tic agent, around 70% conversion of the su fur dioxid to sulfur trioxicl. This particular percentage of conversion is merely given by way of example, since, under favorable conditions, such as exists in commercial ractice, somewhat higher conversion yields can be attained.

A very important feature of the use of mineral alunite as a catalyst is the fact that the mineral is enhanced in value by such use. Raw or native alunite, while it contains valuable amounts of the sulfates of potassium and aluminum, is insoluble in water, and therefore these constituents are unavailable Without a strenuous preliminary treatment. When, however, the alunitc is used as a cata lyst, in the contact process for producing sulfur trioxid, it is affected in such a Way that the available constituents thereof become soluble in water. Accordingly, when the alunite is removed from the catalytic chamber, crushed and extracted with hot Water, the solution yields, on evaporation, a practically pure potash alum which is the hydrated double sulfate of potassium and aluminum (K. .Al (SO,),,.24H O). This salt in itself, is a valuable article of com mcrcc and from it there can be prepared various potassium and aluminum salts.

The utilization of mineral alunite as the catalyst, in conjunction with the very advantageou change in its water-soluble properties as a result thereof, is one'of the distinct novelties of the present invention. In

ploying alunite as the catalyst in accordance w1th the present invention, it is desirable and of advantage to use as large quantities of catalyst as possible and to change the catalyst "as often as is compatible with, efiicient yields of sulfur trioxid and water soluble constituents, in order to produce as large a tonnage as possible of water soluble potash salts. Thus, by the contact process. of

the present invention, not only is there obtained a considerable conversion of sulfurdioxid to sulfur trioxid, but at the same time the potassium, aluminum and sulfur trioxid contents of the mineral alunite are rendered available.

The process of the present invention, while it primarily involves the production of sulfur trioxid or sulfuric acid by the contact method, at the same time involves the treatment of mineral alunite to render the available constituents thereof soluble in water. From the'foregoing description, it will be seen that these two aims, namely, the production of sulfur trioxid and the treatment of alunite, are accomplished at one and the same timeby the same methods of procedure.

1 Thus, as far as the procedure itself is conby the cerned, the process of the present invention is the same whether it be considered as a process for producing sulfur trioxid by the mineral alunite at a temperature appropriate to the catalytic oxidation; substantially as described.

2. The process of mak ng sulfuric acid by I the contact method and simultaneously produclng a water soluble double sulfate of potassium and aluminum which comprises bringing a gaseous mixture containing a sulfur dioxid and oxygen into contact with m neral alunite at a temperature appropriate to the catalytic oxidation, thus forming sulfur trioxid by the catalyticaction of the.

alunite, and subsequently dissolving in watcr the double sulfate of potassium and aluminum of the alunite rendered soluble by its action as a catalyzer; substantially as described.

3. The process of making sulfur trioxid by the contact method which comprises bringing a mixture of sulfur dioxidand oxygen into contact with alunite at a temperature appropriate to the catalytic oxidation; substantially as described.

.4. The process of making sulfur trioxid by the contact method,- which comprises bringing a gaseous mixture containing sulfur dioxid' and oxygen at a tem erature from about 450 C. to about550 into contact with alunite; substantially as described.

5. The process of making sulfur trioxid by the contact method which comprises bringing a gaseous mixture containing sulfur. dioxid and oxygen into contact with a native mineral consisting essentially of a hydrated basic double sulfate of potassium and aluminum at a temperature appropriate to the catalytic oxidation; substantially as ,de: scribed.

'6. In a process of making'sulfur trioxid by the contact method, a catalytic agent comprising. alunite; substantially as described. v

7. The process of producing a water soluble double vsulfate of potassium and aluminum from alunite which comprises subjecting the alunite to the action of a gaseous mixture OfSlllfuhtlloXld and oxygen at a temperature from about 450 C. to about 550 (3.; substantially as described.-

8. The process of rendering the naturally insoluble double sulfate of potassium and aluminum of mineral alunite soluble in water, which comprises subjecting the alunite as a catalytic agent in'the contact process for making sulfuric acid to the action of a mixture of sulfur dioxid and oxygen at a temperature appropriate to the catalytic oxidation of the sulfur describeth 9. The process of treating alunite which comprises subjecting the-alunite as a catalytic agent to the action of sulfur dioxid and oxygen at a temperature appropriate to the catalytic oxidation of the sulfur dioxid; substantially as described.

In testimony whereof I afiix my signature.

HERBERT HENRY MEYERS.

dioxid; substantially as 

